31results about How to "Control supersaturation" patented technology

The invention relates to a method for preparing nano catalytic composite materials by utilizing an integrating process of an ultrasonic-film-anti-solvent method, comprising the following steps of: (1) the ammonium porchlorate saturated solution preparation process: dissolving ammonium porchlorate into a proper solvent to prepare the ammonium porchlorate saturated solution at certain temperature; (2) the dispersing process of a nano catalyst: uniformly dispersing the nano catalyst into an anti-solvent under ultrasonic action; (3) the preparing process: adding the AP (ammonium porchlorate) saturated solution to a nonsolvent through a film tube under certain pressure, wherein after the anti-solvent carries out desolvation on the solvent, the ammonium porchlorate is separated out and covers on the surfaces of uniformly-dispersed nano particles to form the nano catalytic composite materials; (4) filtering and drying processes: firstly carrying out solid-liquid separation on nano composite particles; and (5) the drying process: drying separated materials at 50-150 DEG C to obtain the nano catalytic composite materials. The nano catalytic composite materials prepared by the method have stable structure, uniform nano catalyst dispersion and controllable particle diameter and appearance.

The invention provides a new technology of applying the double-effect forced circulation concentration method in the production of ammonium phosphate, which comprises the steps of carrying out double-effect forced circulation flash distillation on phosphoric acid slurry, removing excess moisture in the phosphoric acid slurry and reacting with neutralizing slurry so as to generate intermediate slurry, enabling the intermediate slurry to be reacted with ammonia gas to generate a product, carrying out one-effect forced circulation flash distillation on the product slurry, further preparing qualified monoammonium phosphate slurry, drying and granulating by a fluid bed, packaging and weighing. Heat quantity generated by neutralization reaction is taken as a one-effect flash distillation heat source, and the excess heat in the one-effect flash distillation process is taken as a double-effect flash distillation heat source. With the adoption of the new technology, the heating steps in the production process are reduced, the quantity and height of devices used are decreased, heat energy is used reasonably, and energy consumption is reduced. The temperature difference between an inlet and an outlet of a heater is only 1-3 DEG C, degree of supersaturation can be controlled effectively, and scaling of the pipe wall of a heat exchanger is reduced. The forced circulation can enable the circulation speed of liquid phase to improve greatly, wash the wall pipe, and play an important role in reducing the scaling. The cycle of operation of a device is increased greatly, productive capacity is improved obviously, and the production cost is reduced effectively.

The invention provides a device for accelerating desorption of PM2.5 (Particulate Matter 2.5) fine particulate matters by utilizing vapor phase change and condensation. The device comprises a group of desorption towers which are sequentially connected, wherein flue gas inlets are formed in the bottoms of the desorption towers, flue gas outlets are formed in the tops of the desorption towers, and stream inlets are formed in the side walls of the desorption towers. According to the device, the structure is simple, and the cost is low; and by arranging a group of the desorption towers which are sequentially connected, the supersaturation degrees of the desorption towers are effectively controlled, so that the PM2.5 fine particulate matters in the gas are desorbed step by step; and the efficiency is high, and the energy consumption is low.

The invention discloses a preparation process and device system for continuous cooling and crystallization of ethyl carbazole, which solves the problem that floating crystals are prone to appear in the process of preparing ethyl carbazole in the traditional process, resulting in high moisture content of crystals and easy preparation of powdery crystals. question. The invention includes a preparation process of continuous cooling and recrystallization of ethyl carbazole. The ethyl carbazole crude product and ethanol solvent are mixed according to the mass ratio, and after heating and dissolving, the temperature is lowered for the first time, and the solution temperature is reduced to a supercooling degree of 1 ℃~4℃, add ethyl carbazole seed crystals with a particle size of 0.05mm~0.1mm, keep warm, and then lower the temperature to the crystallization temperature for the second time to obtain the mother liquor of continuous crystallization. Ultrasonic treatment is carried out on the pre-configured raw material solution, and the crystallization time is controlled, followed by centrifugation, washing and drying to obtain ethyl carbazole granule products; the above-mentioned preparation process is used to provide the device system. The invention has the advantages of being able to continuously cool and recrystallize to prepare short rod-shaped ethyl carbazole, and at the same time completely avoid the generation of floating crystals.

The invention specifically relates to a method for prolonging the shelf life of thiourea dioxide products. The technical plan is: under the conditions of 0~30°C and 300~600r / min rotating speed, add crystal seeds to the saturated aqueous solution of thiourea dioxide, grow the crystals, and obtain a suspended crystal slurry; then add and dissolve the suspended crystal slurry Analyzing agent, elution crystallization, filtration and drying to obtain thiourea dioxide crystals, the crystal product meets HG? High stability requirements in the 3258-2010-T industrial thiourea dioxide standard, and its thermal stability ≥ 60min. The thiourea dioxide crystal product produced by the invention has the advantages of concentrated particle size distribution, crystalline luster on the surface, high purity, good thermal stability, etc., can effectively improve the quality of the thiourea dioxide product, improve the safety performance of its transportation and storage, and prolong the shelf life of its product.

The invention relates to the field of a technology for preparing tripotassium phosphate from wet-process phosphoric acid, especially relates to a method for preparing tripotassium phosphate from wet-process phosphoric acid. The method comprises the following steps: a content of sulfate radical in the wet-process phosphoric acid is analyzed, and rock phosphate is added, so that sulfate radical, iron ion and aluminium ion and other cations as well as fluorine ion, silicon ion and other anions form precipitation; ammonia gas or ammoniacal liquor is added, pH value is adjusted to 3-7, so that a solution of ammonium phosphate is formed, after filtering, the formed precipitation is left in the residue liquid by filtering, so that the wet-process phosphoric acid is purified, and the purity of the tripotassium phosphate produced by subsequent production is ensured. After a reaction between an ammonium phosphate slurry and potassium hydroxide or potassium bicarbonate or potash is carried out, an evaporative crystallization is carried out at a negative pressure of 0-0.01MPa, so that the quality of the tripotassium phosphate crystal is good, the purity is high, the consumption of potassium ions is reduced, the production cost is reduced, and resource waste is avoided.